Recently, micro-scale manufacturing technologies, even nano-scale manufacturing technologies have been gradually applied in various technical fields such as semiconductor, optoelectronics, biomedicine, precision machine and the like, and hence a positioning control technology with high accuracy and fine adjustment which can fulfill requirements of various precision processes is desirable. Moreover, in precision measurement instruments such as optical measurement instruments, it is necessary to perform accurate position adjustments to the instruments to achieve desired performances or functions. For example, in testing instruments for a solid immerse lens (SIL) near-field optical head, a precise distance adjustment is required in order to observe near-field optical phenomenon, such as evanescent wave.
At the present day, a micrometer, a precision motor, a piezo-actuator, a magnetic actuator or the like is generally used as a positioning control device of the precision manufacturing equipments or the precision measurement instruments. However, these positioning control devices are restricted to their own structures and therefore have many drawbacks, such as being unable to achieve a more accurate positioning control, slow positioning speed, and high manufacturing cost etc.
In view of the above-described requirements and drawbacks, U.S. Pat. No. 5,187,876 discloses a precision motion transducer which can convert relatively large motion inputs into relatively small motion outputs. As shown in FIG. 1, the precision motion transducer 8 comprises: a deformable elastic transducer body 81 provided with two cantilever beams 811, 812; a micrometer 82 fixed on the cantilever beam 811 for applying calibrated and known motions to an end portion of the cantilever beam 812; a fixing means 83 for fixing the elastic transducer body 81 to a foundation of a equipment; a means 84 for blocking and directing motions, including cutout patterns 841, 842 formed in the elastic transducer body 81, the cutout patterns being designed for directing the motion of the elastic transducer body 81 to an object body to be moved in a desired direction; and an output means 85 for outputting the converted motion to the object body. A known motion is inputted to the deformable elastic transducer body 81 by the micrometer 82 to produce a deformation between the cantilever beams 811, 812. Since the designed cutout patterns 841, 842 have been formed in the elastic transducer body 81 in advance, the deformation can be converted into a motion output at a predetermined location in a predetermined direction (i.e. the shear direction). By designing the sizes of the cantilever beams 811, 812, the rigidity of the elastic transducer body 81, and the sizes and the positions of the cutout patterns 841, 842, a precision motion transducer 8 with a desirable input/output conversion ratio can thus be obtained.
However, though the above-described precision motion transducer 8 is provided with a very high conversion ratio (i.e. with a capability to perform a very fine motion control) and a relatively simple structure, the moving distance of the motion input and/or motion output thereof is restricted to be within a very small range. Moreover, since the motion is converted via the elastic deformation in the shear direction, the converted motion output may not entirely moved toward a desired direction, even the elastic transducer body 81 being formed with the cutoff patterns 841, 842.
Accordingly, there is an urgent need to provide a precision motion transducer, with a simple structure and a high conversion ratio, whereby relatively large motion inputs can be converted to extremely precise motion outputs, while the motion outputs can be completely moved toward a desired direction.